Hi all. I'm sure this topic has been covered, but it's hard to use the search function from my phone internet. I was wondering what oil I should use in my 1946 Farmall M. I bought it about a year ago, and havn't yet changed the oil, yet have always kept an eye on it to be sure it has enough in it. When I start it cold, the gauge goes about 1/4 inch past the end of the high pressure side. It is still 6v, and starts fine in the summer, but in the winter it becomes very slow turning over, and I was told by a neighbor that it is probably due to not having winter oil in it? What oil should I be running in it in these temperatures? (20 degrees and below) I usually run a Non-detergent 30W oil from my local TSC. Thanks.